It is oftentimes necessary to supply heated or cooled air to aircraft on the ground at airports or other equipment having their own air-conditioning systems but which systems are costly and inconvenient to operate while the plane is on the ground. For example, not only is air-craft fuel more expensive than, for example, gasoline or diesel fuel, but also, if the plane's air-conditioning system is used, fuel must be added just prior to take-off of the plane to compensate for the fuel burned in order to run the plane's air-conditioning system.
Typical air-conditioning units or systems include a diesel engine arranged to drive a compressor unit of the air-conditioning system through a mechanical coupling or clutch interposed between the diesel engine and the compressor. Associated equipment needed in such air-conditioning systems are driven mechanically by belts, couplings and the like. Such mechanically driven compressors have crankshaft seals which have a tendency to prematurely fail, thereby releasing large amounts of fluorocarbons to the atmosphere.